Eagles defensive backs coach Cory Undlin remembers studying Ronald Darby a couple years ago when the cornerback was coming out of Florida State. He remembers he liked him.
Since then, though, Darby was drafted by the Bills in the second round of 2015 and Undlin hadn't really thought about Darby very much.
Until last Friday.
"Well, Howie walked into my office and said 'Hey, man, Darby's going to be in your room tomorrow,'" Undlin said Saturday, a week and a day after the trade went down. "I said … 'I'll coach him up when he gets here.'"
Undlin said normally coaches don't really study other NFL players until those players are going to be free agents. Then, they study them like college prospects to see if they'll fit their scheme. Darby wasn't set to become a free agent for two more years.
There wasn't really any reason for Undlin to follow Darby's career.
"I had no idea," Undlin said. "I knew he was a good player. I knew he had a great rookie year, didn't really look at him or follow him much last year."
Since the trade went through, Undlin gave himself a little crash course, watching some of Darby's NFL tape.
What did he come away with?
"It was good," he said. "It was good."
Two days after the trade, Darby partook in his first practice with the Eagles. Six days after the trade, he played in his first game.
Darby played 14 snaps against the Bills on Thursday night and had a pretty good debut. He picked off one pass and should have had another. He showed off his cover ability and his break to the football.
Of course, his coach was quick to point out that it wasn't a perfect debut. Darby missed a tackle against LeSean McCoy on the very first play of the game. There were some technique issues that need to be sorted out. And Undlin said Darby's conditioning isn't where it needs to be yet — he said Darby got "gassed" in his 14 plays.
And then there was the missed interception.
"Would have also liked to see him snatch that first ball when he stepped in front of their sideline," Undlin said. "He should have made that one. You don't get many of those opportunities so I would have loved to see him make that play right in front of their bench. That would have been nice."
If some of those things sound nitpicky, well, they are. For a guy who was on a different team less than a week before the game, Darby had a damn good debut. Undlin knows that and he can already see how talented his new corner is.
Darby is talented enough that Jim Schwartz wasted no time tossing him in with the starting defense on his first day.
We know Darby will definitely be a starter and based on the first preseason game and practices, it looks like he'll be the starter on the left side of the defense. That’s where he's been the first two years of his career. But during this training camp in Buffalo, the Bills worked him on the right side and the Eagles will use him on both sides.
That leaves the possibility that he might travel to line up against other teams' best receivers in 2017.
"That'll come down the road when we play somebody where we feel like we have to do that," Undlin said. "Right now, we're not ready to make that decision. Too early for that."
Undlin is still learning about his new top cornerback. We're not even two weeks removed from the trade.